#json_c.py
import json
element = '''
[
{
    "name":  "Franz",
    "alter":  27,
    "hobby": "Python",
    "kinder": 0
},
{
    "name":  "Karin",
    "alter":  25,
     "hobby": ["Python","Java","C++"],
     "kinder": 0
},
{
    "name":  "Beate",
    "alter":  37,
    "hobby": "Node-Red",
    "kinder": {
                "name":  "Paul",
                "alter":  7
                }              
}
]
'''
json_str = json.loads(element)
#print(json_str)
print(json_str[2]['kinder']['alter'])

with open('text_json_3.json','w') as datei:
    datei.write(json.dumps(json_str, indent=4))